The proposal is based on an unchanged valuation of 9.1 billion euros ($10.7 billion) for the whole of Autostrade, but asks the infrastructure group to cover for much less than 1.5 billion euros in potential legal risks, improving the terms of a previous offer it presented in February, the sources said.

It also allows Atlantia to keep subsidies Rome is expected to grant Autostrade as part of support offered to companies in the wake of the pandemic.

CDP, together with co-investors Macquarie and Blackstone, have been negotiating with infrastructure group Atlantia over Autostrade since last year to try to end a dispute triggered by the 2018 collapse of a bridge ran by the unit, which killed 43 people.

CDP approved the bid on Wednesday and Atlantia is expected to hold an informal meeting on Thursday to discuss it.

A formal assessment will probably have to wait until next week when the Atlantia board must decide if the offer is attractive enough to bring to shareholders.

On Monday the Benetton family and Italian banking foundation CRT, both key Atlantia investors, blocked a shareholder proposal to extend a plan to spin off Autostrade.

The vote exposed a rift among investors and raised question marks over the reception of the revised offer by Atlantia's minority shareholders, including activist hedge fund TCI, which repeatedly said that 100% of Autostrade is worth no less than 12.5 billion euros.

Germany's Allianz and funds DIF, EDF Invest and China's Silk Road Fund own 12% of Autostrade.

($1 = 0.8527 euro)

(Reporting by Giuseppe Fonte and Francesca Landini in Rome Editing by Chizu Nomiyama and Matthew Lewis)

By Giuseppe Fonte and Francesca Landini